Vermilacinia pumila is a whitish-green fruticose lichen that occurs in fog areas along the Pacific Coast and offshore islands of North America.

Vermilacinia pumila is classified in the subgenus Vermilacina in which it is distinguished by its small hemispherical thallus of densely compacted, erect but curved stubby branches (crowded together, touching) not more than 1 cm high, and generally 1–2 mm in diameter.

[1] This is in contrast to the taller and narrower, loosely aggregate branches (not touching) of V. combeoides, 2–4 cm high, and not more than 1 mm in diameter.

[1] Vermilacinia pumila seldom produces the terminal apothecia that is generally characteristic of V. combeoides; instead, its branches frequently bifurcate into narrower lobes that abruptly taper to a pointed apex.

Prior to then, it was seen as variation of V. combeoides; however, Peter Bowler and collaborators had identified the type specimen of V. pumila (before the species was described, collected by William Weber and C. J. McCoy, L-36641) from Guadalupe Island, and one other from Santa Cruz Island (collected by Rudolf M. Schuster)[4] as belonging to Niebla ceruchoides (= Vermilacinia ceruchoides), which led to its treatment as a synonym in the Lichen Flora of the Greater Sonoran Desert.